package com.xing.reggie.controller;

import com.xing.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.util.UUID;

/**
 * 文件上传和下载
 */
@RestController
@Slf4j
@RequestMapping("/common")
public class CommonController {

    @Value("${reggie.path}")
    private String basePath;

    /**
     * 文件上传
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){

        //使用原始文件名
        String originalFilename = file.getOriginalFilename();
        //获取文件格式，就是文件名后缀
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
        //使用UUID来命名，防止文件名重复被覆盖
        String fileName = UUID.randomUUID().toString()+suffix;
        //创建一个目录文件
        File newFile = new File(basePath);
        //判断是否存在，
        if (!newFile.exists()){
            //不存在则创建新目录
            newFile.mkdirs();
        }
        //file为临时文件，需要转存到指定位置，负责本次请求完成后临时文件会自动消失
        try {
            file.transferTo(new File(basePath+fileName));
        } catch (IOException e) {
            e.printStackTrace();
        }
        log.info(file.toString());
        //返回文件名给前端页面
        return R.success(fileName);
    }

    /**
     * 文件下载
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response) throws IOException {

        //1.输入流，通过输入流读取文件
        FileInputStream fileInputStream = new FileInputStream(new File(basePath+name));

        //2.输出流，通过输出流将文件输出到浏览器
        ServletOutputStream outputStream = response.getOutputStream();

        //设置输出类型，图片格式
        response.setContentType("image/jpeg");
        int len = 0;
        byte[] bytes = new byte[1024];
        while ((len = fileInputStream.read(bytes)) != -1){
            outputStream.write(bytes,0,len);
            outputStream.flush();
        }
        //关闭资源
        outputStream.close();
        fileInputStream.close();
    }


}
